Chapter 14. Biology and Diseases of Ferrets Flashcards
1
Q
Ferret taxonomy
A
Family Mustelidae
Subfamily Mustelinae
Genus Mustela
Mustela putorius furo
2
Q
Subfamily Mustelinae
A
Includes weasels, mink, ferrets (genus Mustela), martens (genus Martes)
3
Q
Genus Mustela
A
5 subgenera: Mustela (weasels), Lutreola (European mink), Vison (American mink), Putorius (ferrets) Grammogale (South American weasels)
4
Q
Family Mustelidae
A
- Smallest member = least weasel (Mustela nivalis)
- Largest member = sea otter (Enhydra lutris)
5
Q
Ferret use in research
A
- Influenza pathogenesis
- Virology
- Neuroscience
- Carcinogenesis
- Cardiovascular physiology
- Emesis
6
Q
Sources of ferrets
A
- Large-scale commercial production (available in US) - inbreeding related to disease susceptibility?
- Fur operations
7
Q
Commercials stocks of ferrets
A
-Based on coat color: albino, sable (‘fitch’, ‘wild’; most common), Siamese, silver mitt, Siamese-silver mitt (Siamese with white chest and feet)
8
Q
US ferrets with blaze or white head
A
- Up to 75% can have Waardenburg syndrome & are deaf
- Physiologic basis: ipsilateral projections of the cochlear nucleus to the auditory midbrain in albino ferrets
- Albino ferrets also have impaired motion perception & contrast sensitivity
9
Q
Recommended temperature ranges for ferrets
A
- Tolerate low temps well & high temps poorly
- Juveniles & adults: 4-18 C (39.2-64.4 F)
- <6 weeks old: greater than 15 C; kits under this age require a heat source if separated from dam; older group-housed kits do not
- Elevated temps (>30 C; 86 F) cannot be tolerated by ferrets
10
Q
Why can’t ferrets tolerate high temperatures?
A
Poorly developed sweat glands = susceptible to heat prostration
-Signs of heat stroke: panting, flaccidity, vomiting
11
Q
Recommended humidity range for ferrets
A
40-65%
12
Q
Recommended lighting for ferrets
A
- 12:12 dark-light appropriate for non-breeding animals housed for <6 months
- 16 hr light daily for breeding and lactating jills
- Ferrets maintained beyond 6 mths should be exposed to a ‘winter’ = 6 weeks per year of 14 hr dark daily to maintain physiologic normalcy
13
Q
Light cycle for time-pregnant jills
A
Maintain light cycle that time-pregnant jills were exposed to prior to shipment; failure to do so can results in negative energy balance & pregnancy toxemia
14
Q
Recommended air changes for ferret housing
A
- 10-15 air changes per hour
- Use nonrecirculated air b/c of strong ferret odor & susceptibility of ferrets to human respiratory tract infections
- Ferret odor should not overlap any rodent housing areas b/c rodents have instinctive fear of ferrets; scent can disrupt rodent breeding and physiology
15
Q
Social housing of ferrets
A
- Females can be housed singly or in groups
- Estrous females that are cohoused may become pseudopregnant
- Intact males should be housed individually after 12 weeks of age
- Weanling ferrets (4- 12 week old) may be group housed
16
Q
Spacing of grid wall for ferret caging
A
1 x 0.5 inches apart, or 0.25 inch if using wire mesh
17
Q
Potentional health concerns for ferret caging
A
- Zinc toxicosis reported in ferrets licking galvanized bars from which metals had leached during steam sterilization
- Clay litters can cause chronic upper resp infx due to inhaled dust
18
Q
Cage size for ferrets
A
24x24x18 inches = adequate for 2 adults
19
Q
Diet parameters for ferrets
A
- Protein source: meat
- Nonbreeding adults = 18-20% fat, 30-40% protein
- Breeding adults = 25% fat, minimum 35% protein
- Peak lactation = minimum 30% fat, minimum 35% protein
20
Q
Food and water consumption of ferrets
A
- Feed ad libitum
- Food: 43 g/kg body weight
- Water: 75-100 mL daily
21
Q
Enrichment for ferrets
A
- Sleeping locations: snooze tube, hammock, PCV pipe or dryer hose
- Digging behavior: box filled with rice, plastic balls, crumpled paper balls
- Enrichment lowers fecal glucocorticoid metabolites (FGM) in juvenile males; this study also showed juvenile males interacted with enrichment more than juvenile females (no effect on juvenile female FGM)
22
Q
Unique anatomy of ferrets - thorax
A
- Thorax is narrow & elongated with proportionally long trachea = good for studies of tracheal physiology
- Tracheal size & laryngeal anatomy make intubation somewhat challenging = ferrets used for pediatric intubation training
- Lung relatively large; total lung capacity is nearly 3x what would be predicted based on body size compared to other mammals = pulmonary research model
- Higher degree of bronciolar branching with more extensive bronchial submucosal gland compared to dog = pulmonary research model
- Paired common carotid arteries arise from the brachiocephalic trunk at the level of the thoracic inlet (like dogs & cats)
23
Q
Unique anatomy/physiology of ferrets - abdomen
A
- Carnivore = simple monogastric stomach
- NO cecum; indistinct ileocecal transition makes it difficult to identify junction of small and large intestines grossly
- Length of alimentary tract is very short relative to body size = GI transit time as short as 3 hr
- Extramedullary hematopoiesis common in spleen; can result in splenomegaly
- Ferrets have no naturally occurring antibodies against unmatched erythrocyte antigens & none develop even with repeated transfusions
24
Q
Scent glands of ferrets
A
- Paired anal scent glands; well-developed
- Animals can be descented surgically
- Some animals, especially intact males & estrous jills, may still have musky odor even after descenting because of normal sebaceous secretions
25
Q
Sweat glands of ferrets
A
-Ferrets lack well-developed sweat glands = predisposed to prostration when ambient temps reach 32 C (90 F)
26
Q
Unique anatomy/physiology of ferrets - reproductive
A
- Seasonal breeders
- Prolonged estrus in unbred females can result in aplastic anemia - can reproduce this with exogenous estrogen administration
- Males has os penis & prostate gland
27
Q
Ferret weight ranges
A
- Newborn kits: 6-12 g at birth
- 6-8 weeks: 400 g
- Intact males: 1-2 kg
- Intact females: 0.5-1 kg
- Gonadectomized adults: 0.8-1.2 kg
- Body weight can fluctuate up to 30-40% with seasonal changes
28
Q
Ferret lifespan
A
6-8 years; rarely up to 11 years
29
Q
Normal body temperature for ferrets
A
38.8 C (37.8-40 C)
30
Q
Chromosome number for ferrets
A
40 (diploid)
31
Q
Dental formula for ferrets
A
2 (I 3/3, C 1/1, P 4/3, M 1/2)
32
Q
Vertebral formula for ferrets
A
C7-T15-L5-S3-C14
33
Q
Age of sexual maturity for ferrets
A
4-12 months
-Length of breeding life is 2-5 years
34
Q
Gestation length in ferrets
A
42 +/- 2 days
-Litter size 1-18, average 8
35
Q
Kit development in ferrets
A
- Birth weight: 6-12 g
- Eyes open: 34 days
- Onset of hearing: 32 days
- Weaning: 6-8 weeks
36
Q
Erythron in ferrets
A
-Ferrets have relatively robust erythron, with Hct, Hbg, and total RBC & reticulocyte counts generally higher than dog or cat
37
Q
Proteinuria in ferrets
A
- A low grade proteinuria on UA may be seen in normal, healthy ferrets
- Normal USG in intact males: 1.051, intact females: 1.042
38
Q
Ferret nutrition
A
- Strict carnivores
- Short GI tract & rapid GI transit time require protein to be readily digestible
- Daily maintenance energy requirement: 0.5 MJ metabolizable energy (ME)/kg metabolic body weight (BW^0.75)
- In MINK: 42% protein up to 16 weeks; after 16 weeks old, 26-36% protein, 9-28% fat, 22-42% carbohydrate
- 30-40% protein & 18-20% fat for adults; minimum 35% protein & 25% fat for reproductively active & growing animals
- Diets high in fish or with raw meat not recommended
- Digestibility of crude protein in ferrets significantly lower than cats & digestibility of crude fat significantly higher = ferrets cannot be used as a model of cats & careful comparing data between two species
- Carbohydrates should not exceed 30-36% for adults, but kits feed carb-free diet reported to do poorly d/t hypoglycemia
39
Q
High levels of plant protein in ferret diets
A
Can lead to urolithiasis
40
Q
Ferrets in Beta-carotene research
A
- Used to investigate absorption, metabolism, interaction of Beta-carotene & Vit E
- Ferrets, like humans, convert Beta-carotene to Vit A in the gut & absorb Beta-carotene intact
- Beta-carotene, retinol & retinyl esters are absorbed intact into the lymph & cleavage products (Beta-apo-12’-carotenal, Beta-apo-10’-carotenal, retinoids) accumulate in intestinal mucosa - mucosa converts Beta-carotene into retinoic acid - transported via portal vein to liver
- Beta-carotene absorption & conversion into retinol enhanced by coperfusion of alpha-tocopherol
- Ferrets able to excrete retinol & retinyl esters into urine - depends on oral Vit A supplementaton
- Lung cancer model of ferrets exposed to tobacco smoke has been used to evaluate the cancer-modulating properties of these micronutrients
41
Q
Ferret water consumption
A
- 75-100 mL per day, depending on dry matter content of feed
- Provide fresh water ad libitum in secured bowels or water bottles (ferrets will overturn is not well secured)
42
Q
Ferret reproductive calendar
A
- Seasonal breeders
- In the wild, season in Northern Hemisphere is March-August for females & December-July for males
43
Q
Estrous cycle in ferrets
A
- -Puberty: 6-12 months
- Minimum breeding age: 8-12 mths male, 4-5 mths female
- Monestrous, continuous duration until intromission
- Induced ovulators
- Jills maintained at 8 hr light-16 hr dark reach puberty in 10-12 months
- The transfer from short to long photoperiods should not occur prior to 90 days of age, b/c jills that are prematurely transferred will remain anestrous
44
Q
Gestation period in ferrets
A
42 +/- 1 day
-Average litter size 8 (1-18)
45
Q
Estrus in ferrets
A
- Vulvar swelling is hallmark sign
- NOT assoc w/ rising FSH like in rodents
- Mated ~14 days after vulvar enlargement
- Estradiol concentrations responsible for development of female reproductive tract & secondary sexual characteristics
- Tonic inhibition of LH secretion by the anterior pituitary during both prepubertal life and anestrus
- With increasing light exposure, LH levels rise despite estradiol
- Jills may return to estrus during 2nd-3rd week of lactation if they have fewer than 5 kits, or 2 weeks after weaning if litter is larger
- Jills should be rebred or given hCG to terminate estrus, even if still lactating
- May have 2-3 litters yearly until 5 years old
- A nonstimulatory photoperiod should be used 6 weeks per year to rest the ferret and preserve maximum fertility - jills return to estrus ~3 wks after reinstitution of longer photoperiod
- Return of estrus correlates with follicular development and increased plasma estradiol
46
Q
Reproductive physiology of male ferrets
A
-Age differences in the sensitivity of negative feedback inhibition of the hypothalamic secretion of gonadotropin-releasting hormone (GnRH) by testosterone, or to estrogenic compounds derived from aromatization of testosterone, appear to be essential in determining puberty & seasonality of reproduction in males
47
Q
Ovulation in ferrets
A
5-13 ova ovulated 30-40 hr after coitus = induced ovulators
- Neck restraint and intromission by the male required for ovulation
- Implantation occurs 12 days after mating
48
Q
Placentation of ferrets
A
-Zonary & endotheliochorial (typical for carnivores)
49
Q
Pregnancy detection in ferrets
A
- Ultrasound detection as early as day 12
- Palpation as early as day 14
- Calcified fetal skeletons on radiographs at ~30 days
50
Q
Husbandry needs of pregnancy ferrets
A
- Separate to single housing when within 2 weeks of parturition
- Provide nest box with bedding for warmth
- Next box should be at least 6 inches deep
- Nutritional support very important: risk for pregnancy toxemia = hypoglycemia, hyperketonemia, hypoinsulinemia, decreased T4 & T3, hepatic lipidosis
51
Q
Parturition in ferrets
A
- Rapid, as little as 2-3 hr
- Primiparous jills usually deliver on day 41, multiparous on day 42
- Fetuses remaining in utero beyond day 43 typically die
- Dystocia is common d/t positional abnormalities and fetal oversize = C-section; failure to deliver within 8 hr after administration of prostaglandin is indication for C-section
- Leave undisturbed for several days postpartum to minimize cannibalization
- Fostering: allow pups to mingle with foster jill’s own pups while jill is away so that rejection d/t olfactory stimuli will not occur
52
Q
Development of newborn ferrets
A
- Born altricial; dependent on jill for first 3 weeks
- Coat color starts to become visible at 3 days of age
- Weigh 6-12 g at birth
- Sexual dimorphism in size apparent by week 7
- Eruption of deciduous teeth = 14 days
- Ability to hear = 32 days - ear canals do not open until 32 days - startle response in kits
- Opening of eyes = 34 days
- Eruption of permanent canines = 47-52 days
- Displacement of deciduous canines by 56-70 days
- POLECATS = learn scent of prey between 60-90 days
53
Q
Weaning in ferrets
A
- 6 weeks of age
- Can give slurry of adult food with fat supplementation to achieve 30% fat (Linatone supplement)
- Diet should be 30% fat, 40% protein
- Group housed until sexually mature
- Males >12 weeks old may fight if exposed to greater than 12 hr of light per day
54
Q
Clostridium perfringens Type A - etiology, transmission
A
- Etiology: Clostridium perfringens Type A
- Ubiquitous, present in GI tracts of humans & animals
- Acute abdominal distenstion, dyspnea, cyanosis in weanling ferrets
- Predisposing factors: overeating, sudden changes in diet, proliferation of C. perfringens type A & its toxins
55
Q
Toxins of Clostridium perfringens Type A
A
-Alpha toxin: principal lethal toxin; hemolytic and necrotizing & has ability to split lecithin or lecithin-protein complexes, leading to destruction of cell membranes & necrosis
56
Q
Clostridium perfringens Type A - clin signs, diagnosis
A
- Clin signs: acute abdominal distension, cyanosis, found dead & bloated
- Diagnosis: isolation of bacteria from stomach/intestines; toxin identification using mouse protection assay
- Necropsy findings: markedly distended stomach & intestines with large amount of gas & brown semiliquid ingesta; SC emphysema
- Histo: abundant G(+) bacilli in smears of gastric and intestinal contents; GI mucosa necrosis, G(+) baclli lining denuded mucosal surface & extending into gastric glands, intestinal crypts; lymphoid necrosis of LNs, spleen, thymus; mild to moderate dilation of central hepatic sinusoids with hepatocellular dissociation and multifocal aggregates of necrotic neutrophils within portal areas
57
Q
Clostridium perfringens Type A - treatment, control
A
- Prevention: good management & feeding practices; restrict feeding of weanlings to 2x instead of 3x daily
- Tx: supportive care, gastric trocharization - these can be unrewarding
58
Q
Campylobacteriosis - etiology, transmission
A
- Etiology: Campylobacter jejuni; G(-) spirally curved microaerophilic bacteria
- Causes diarrheic illness in humans, dogs, cats, cows, goats, pigs, mink, ferrets, sheep; mastitis in cows, infectious hepatitis in chickens; abortion in cattle, sheep, goats, dogs, mink
- Can be cultured from asymptomatic dogs, cats, ferrets
- Transmission: ingestion of organisms through direct contact with feces or contaminated feed & water
59
Q
Campylobacteriosis - clin signs, diagnosis
A
- Clin signs: self limiting diarrhea; anorexia, dehydration, tenesmus; fetal resorption, abortion
- Diagnosis: based on history, clinical signs, culture - grows slowly & need selective media or filtration techniques w/ temp 42-43 C & microaerophilic conditions; round, raised, translucent & sometimes mucoid colonies
- Ddx: proliferative bowel disease, other infectious and noninfectious causes of diarrhea
60
Q
Campybacteriosis - pathology, treatment, control
A
- Necropsy findings: neutrophilic infiltrates in lamina propria of colon; enterocolitis; placentitis
- Tx: supportive care, antibiotics based on C&S; azithromycin & fluoroquinolones commonly used in humans; experimental killed whole cell vaccine protected 80% of ferrets when given 4 doses 48 hr apart
- Control: ZOONOTIC = isolate positive animals; good hygiene
61
Q
Helicobacter mustelae - etiology, transmission
A
- Isolated from margins of a duodenal ulcer of a ferret
- Every ferret with chronic gastritis is infected with H. mustelae; SPF ferrets do not have gastritis, gastric ulcers, or detctable IgG antibody
- Robust model for H. pylori gastritis in humans
- Colonizes nearly 100% of ferrets shortly after weaning; may be due to fecal-oral transmission
- Ferrets placed on proton pump inhibitors, which raise gastric pH, have a statistically higher recovery of H. mustelae from feces when compared with age-matched untreated control ferrets
- Ferret is ONLY domesticated animal to date with naturally occurring helicobacter associated ulcer disease
62
Q
Helicobacter mustelae - clin signs, diagnosis
A
- Clin signs: gastric or duodenal ulcers - vomiting, melena, chronic weight loss, lowered hematocrit; gastric adenocarcinoma - vomiting, anorexia, weight loss
- Ddx: gastric foreign body
- Dx: endoscopy; gastric samples inoculated onto blood agar plates supplemented with trimethoprim, vancomycin, polymixin B - incubate at 37 or 42 C in a microaerobic atmosphere for 3-7 days; H. mustelae = produce urease, catalase, oxidase; resistant to cephalothin; sensitive to nalidixic acid
63
Q
Helicobacter mustelae - pathology, treatment, control
A
- Superficial gastritis with H. mustelae on surface of mucosa but NOT in crypts; diffuse antral gastritis; focal glandalar atrophy (a precancerous lesion) & regeneration; can see deep colonization focally in antrum
- Argyrophilic bacteria in liver, biliary tract - chronic cholangiohepatitis, bile duct hyperplasia, cholangiocellular carcinoma (H. cholecystus)
- Susceptible to gastric cancer = gastric adenocarcinoma, gastric mucosa associated lymphoid tissue (MALT) lymphoma
64
Q
Helicbacter mustelae - treatment, control
A
- Tx: triple therapy with amoxicillin, metronidazol, bismuth subsalicylate 3x daily for 3-4 weeks; ranitidine bismuth & clarithromycin 3x daily for 2 weeks
- Eradicaton associated with decrease in anti-H. mustelae IgG antibody titers (consistent with findings in humans)
- Omeprazole induces hypochlorhydria & may be used in conjunction with antibiotics to treat H. mustelae-assoc duoenal or gastric ulcers; cimetidine can also be used to decrease acid secretion; sucralfate for clinical signs of stomach ulcers
- Fluids & blood transfusions for acute bleeding ulcers
65
Q
Proliferative bowel disease in ferrets - etiology, transmission
A
- Etiology: Lawsonia intracellularis = intracellular Campylobacter-like organisms related to Desulfovibrio spp.; G(-), comma to spiral-shaped bacteria
- Transmission: fecal-oral
- Disease of young ferrets
- Copathogens include Campylobacter spp, coccidia, chlamydia
66
Q
Proliferative bowel disease - clin signs, diagnosis
A
- Clin signs: chronic diarrhea, lethargy, anorexia, weight loss, dehydration; diarrhea may be blood-tinged, contain mucus, often green in color; rectal prolapse; ataxia and muscle tremors
- Dx: clinical signs, palpably thickened colon, colonic biopsy
- Ddx: other causes of diarrhea and weight loss
67
Q
Proliferative bowel disease - pathology, differentials, treatment
A
- Segmented, thickened large bowel - usually terminal colon, can also include ileum and rectum
- Histo: marked mucosal proliferation and intracytoplasmic L. intracellularis seen with silver stain in apical portion of epithelial cells; mixed inflammatory infiltrate; reduced goblet cell production; hyperplasia of glandular epithelium; glandular irregularity with penetration of mucosal glands through the muscularis mucosa; increased thickness of tunica muscularis
- Translocation of glandular tissue to extraintestinal sites - regional LNs & liver - has been reported
- Ddx: other causes of diarrhea and wasting, including dietary changes, eosinophilic gastroenteritis, gastric foreign body, lymphoma, Aleutian disease (AD), gastric ulcers
- Incidence appears to be rare
- Tx: supportive care; chloramphenicol or metronidazole for 2 weeks
68
Q
Tuberculosis in ferrets - etiology, transmission
A
- Etiology: Mycobacterium bovis, M. avium, M. tuberculosis
- Aerobic, G(+), non-branching, non-spore-forming, acid-fast rods
- Ferrets might be more susceptible to mycobacterial infections than other species; can have natural infections with M. bovis and M. avium; also susceptible to experimental infx with human tubercle bacillus; endemic in feral ferrets inf New Zealand
- Feeding of commercial diets and TB testing in livestock and poultry has reduced incidence of the disease in ferrets
- Horizontal transmission demonstrated in ferrets under experimental housing conditions
- Den sharing, playing, fighting, sniffing, cannibalism, and aggressive breeding could transmit TB between ferrets
- M. celatum infx reported in one ferret - accurate dx difficult because reacts positively with polyclonal Abs against M. paratuberculosis & M. bovis = identify using 16S rRNA sequence analysis
69
Q
Tuberculosis in ferrets - clin signs, pathology
A
- M. bovis causes typical microscopic foci of infection & necrosis; M. avium may not cause these in all ferrets; human TB causes just localized infx with minor spread to adjacent LNs
- Weight loss, anorexia, lethargy, death, miliary lesions of lungs & other viscera, progressive paralysis
- Mesenteric LNs often infected - related to ORAL infection
- Histo: granulomatous inflamm w/ predominantly macrophages, multnucleated giant cells, epithelioid cells - in lungs, intestines, spleen, liver, peripancreatic adipose tissu; numerous acid-fast bacilli within macrophages
- Impaired cell-mediated response may account for the large number of organisms observed in M. bovis lesions
70
Q
Tuberculosis in ferrets - diagnosis, treatment, control
A
- Dx: isolation of organism in tissue; most common sites = retropharyngeal & mesenteric LNs
- A tuberculin skin testing regimen has NOT been definitively characterized for ferrets yet
- Tx: euthanasia b/c ZOONOTIC; clarithromycin, rifampicin, clofazimine
71
Q
Salmonellosis in ferrets - etiology, transmission
A
- G(-), non spore forming, facultative anaerobic rods in family Enterobacteriaceae
- Genus Salmonella has 2 species: S. bongori = poikilotherms & rarely humans, S. enterica
- Transmission: ingestion from contaminated food or water products
- Serotypes that have been isolated from ferrets include S. Hadar, S. Enteritidis, S. Kentucky, S. Typhimurium
72
Q
Salmonellosis in ferrets - clin signs, pathology
A
- Conjunctivitis, rapid weight loss, tarry stools, febrile, lethargy, anorexia, trembling, abortion/stillbirth
- Gross lesions: tissue pallor, petechiae of gastric mucosa, melena, dark fibrinous exudate in large intestine, GI contents containing lots of mucus, some blood
- Histo: desquamated epithelium of GI mucosa, exudate in small intestine containing mucoid material, RBCs, desquamated intestinal villi; edematous villi in ileum, infiltration of small intestinal mucosa with lymphocytes and macrophages; necrotic foci in liver, spleen, kidney; splenomegaly, visceral lymphadenopathy; necrotizing endometritis
73
Q
Salmonellosis in ferrets - diagnosis, treatment, control
A
- Dx: based on history, clinical signs, isolation of organism - culture on enrichment and selective media
- Tx: sulfathalidine in feed; supportive care; antibiotics based on C&S
74
Q
Pneumonia in ferrets
A
- Streptococcus zooepidemicus & other group C & G streptococci; Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bordetella bronchiseptica
- Primary bacterial pneumonia not very common; may occur secondary to megaesophagus in ferrets, or secondary to influenza
- EXCEPTION: outbreak of Mycoplasma species in ferrets as primary pathogen
- Clin signs: nasal discharge, dyspnea, lethargy, anorexia, increased lung sounds, cyanosis, fever, sepsis, death
- Dx: history, clin signs, CBC, culture and cytology of tracheal or lung wash, radiographs
- Ddx: dilated cardiomypathy, heartworm, mycotic pneumonia, pneumocystis pneumonia in immunosuppressed animals, neoplasia, influenza
- Tx: antibiotics, supportive care, oxygen
75
Q
Abscesses in ferrets
A
- Staphylococcus spp, Streptococcus spp, Corynebacterium spp, Pasteurella, Actinomyces, hemolytic E. coli, Aeromonas spp
- Of lung, liver, uterus, vulva, skin, mammary glands, oral cavity
- May result from wounds inflicted by biting during fighting, playing, mating, chewing sharp objects
- Clin signs: localized swellings +/- draining tracts - usually SC abscesses are walled off & don’t cause systemic signs; may see dental abscesses d/t canine tooth fracture; stranguria d/t prostatic abscessation - often secondary to hyperadrenocorticism
- Dx: cytology & Gram staining of aspirate
- Ddx: myiasis, granuloma, hematoma, neoplasia
- Tx: prevent exposure to sharp objects, limit exposure of male and female during breeding, antibiotics & establish drainage
76
Q
Mastitis in ferrets - etiology, transmission
A
- G(+) cocci like Streptococcus spp, Staphylococcus aureus & coliforms like hemolytic E. coli most frequently associated
- Factors that may be involved: stress of lactation, injury to mammary glands by kits, environmental contamination, virulence of the organism
- Organism may be present in oral cavity of kits
77
Q
Mastitis in ferrets - clin signs, diagnosis
A
- Acute form: occurs soon after parturition or after 3rd week of lactation - glands are swollen, firm, red or purple, painful, may become gangrenous
- Chronic form: may occur when kits are 3 weeks old or as sequela to acute form = glands that are firm but NOT painful or discolored
- Dx: history, clin signs, PE findings, isolation of organism
- E. coli often positive for cnf1 = tend to produce extraintestinal disease & are referred to as necrotoxigenic E. coli
78
Q
Mastitis in ferrets - pathology, treatment
A
- Glands swollen, overlying skin discolored
- Edema, hemorrhage, coagulative & liquefactive necrosis of glandular tissue & surrounding SC tissue
- Mixed leukocytic infiltrate - primarily PMN leukocytes, large numbers of bacteria, thombosis and necrosis of vessels
- Tx: broad-spectrum antibiotics; recommend oral administration of antibiotics to nursing kits also; surgical resection & debridement may be needed for acute mastitis; kits may spread infection to foster jills!; good hygiene to minimize spread to other jills; euthanisia for chronic mastitis
79
Q
Canine distemper in ferrets
A
- Paramyxovirus; genus Morbillivirus (related to measles, rinderpest)
- Several strains, including a ferret adapted strain
- Virus can be inactivated by heat, light, phenol, Roccal, sodium hydroxide, formalin
- Most serious viral infection of ferrets; mortality up to 100%
- Catarrhal Phase: 7-10 days postinfx; anorexia, pyrexia, photosensitivity, serous nasal discharge, erythematus pruritic rash (cell-mediated immunity to infected endothelial cells), hyperkeratosis of footpads (not always seen); secondary bacterial - mucopurulent ocular and nasal discharge, pneumonia
- CNS Phase: ataxia, tremors, paralysis; may or may not be preceded by catarrhal phase
- Death in 12-16 days from ferret strains, up to 35 days from canine strains
80
Q
Canine distemper in ferrets - transmission, epizootiology
A
- Virus shed in conjunctival, nasal, oral exudates, urine, feces, sloughed skin
- Ferrets very susceptible to infection via respiratory route
- Viremia detectable 2 days postinfection & persists until ferret mounts a neutralizing antibody response
- Primary site of replication = respiratory and lymphatic systems
- Decrease in lymphocyte subsets at 5-30 days postinfection
- Moves to CNS via infection of vascular endothelial cells and hematogenous spread of virus infected leukocytes from meningeal blood vessels into the subarachnoid space = widespread infection of cells of pia and arachnoid mater of the leptomeninges over large areas of the cerebral hemispheres
81
Q
Canine distemper in ferrets - clin signs, diagnosis
A
- Intracytoplasmic & intranuclear inclusion bodies in tracheal, bronchial epithelia; bile duct; transitional epithelium of bladder
- Inclusions = eosinophilic (H&E) inclusions, appear orange using Pollack’s trichrome stain
- Dx: fluorescent antibody test on peripheral blood & conjunctival mononuclear cells; RT-PCR; cytology of conjunctival scrapings
- Ddx: Bordetella bronchiseptica, influenza (does not rapidly progress to mucopurulent ocular and nasal discharge like CD)
82
Q
Canine distemper in ferrets - treatment, control
A
- Isolate clinically affected ferrets; euthanasia recommended as no reports of animals surviving acute infection
- Vaccination can prevent infx: MLV of chicken embryo tissue culture origin (CETCO) given IM
- Vaccinate kits every 2-3 weeks from 6 weeks old to 14 weeks, then annually
- Vaccine reactions have been reported following double-dose vaccination (follow schedule above) - vomiting, diarrhea, fever, collapse
- Treat vaccine reaction with diphenhydramine IV or IM or epinephrine SC, IV, IM, intratracheal
- Inactivated vaccines do not deliver consistent effective immunity = NOT recommended
- CD used to experimentally study mobillivirus infection and vaccine strategies in humans
83
Q
Experimental infection of ferrets with viruses
A
- Feline panleukopenia, canine parvovirus, canine parainfluenza, mink enteritis virus, respiratory syncytial virus, transmissible mink encephalopathy, pseudorabies
- Natural infection with these viruses has not been reported
84
Q
Aleutian disease - etiology, transmission
A
- Aleutian mink disease virus (ADV) = parvovirus in genus Amdoparvovirus, species Carnivore amdoparvovirus 1
- Most common strain = ADV-F
- Mink derived strains more virulent to mink than ferrets; at least 3 strains that are distinct from the mink ADV have been documented in ferrets
- Hypergammaglobulinemia (HGG) = immunomodulation that is disruptive to research
- Transmission: direct or via aerosol of urine, saliva, blood, feces, fomites; vertical transmission established in mink but unproven in ferrets
85
Q
Aleutian disease - clin signs, diagnosis
A
- Ferrets infected as adults = persistent infection but rarely disease; chronic progressive weight loss, cachexia, malaise, melena
- May cause ataxia, paralysis, tremors, convulsions
- Lesions typically immune-mediated; elevation of gammaglobulins >20% of the total proteins; in mink there is depression of B & T cell responses
- Dx: HGG and chronic weight loss; IFA or counter-immunoelectrophoresis (CIEP) for antibody to ADV antigen; ELISA & PCR
- Presence of ADV antibody in a ferret is NOT necessarily diagnostic of the disease in an animal (up to 10% of ferrets may be antibody positive without disease)
- DNA of ADV can be detected by in situ hydrixization - can use on paraffin embedded fixed tissues
- Ddx: neurotropic form of canine distemper, chronic wasting diseases like neoplasia, malabsorption, maldigestion, bacterial enteritis
86
Q
Aleutian disease - treatment, pathology
A
- Disinfection with formalin, sodium hydroxide, phenolics
- No general treatment, animals should be euthanized
- Mink kits treated with gamma globulin-containing ADV antibody had decrease mortality rates
- Necropsy: may have no lesions; infrequent hepatosplenomegaly & lymphadenopathy
- Histo: periportal lymphocytic infiltrates; bile duct hyperplasia & periportal fibrosis; membranous glomerulonephritis
87
Q
Influenza in ferrets - etiology
A
- Orthomyxovirus
- Transmissible from humans to ferrets & ferrets to humans = vaccination of handlers, PPE, don’t work with ferrets if having respiratory illness
- Human influenza viruses A & B pathogenic to ferrets (type B low pathogenicity)
- Ferrets also susceptible to avian, phocine, equine, swine influenza - only swine causes clinical signs
88
Q
Influenza in ferrets - clin signs, epizootiology
A
- Remains localized in nasal epithelium but may cause pneumonia
- Clin signs = 48 hr postinfx; anorexia, fever, sneezing, serous nasal discharge, otitis
- Secondary bacterial infection with Streptoccosu spp, Bordetella bronchiseptica
- Transmission: aerosol, direct contact
89
Q
Influenza in ferrets - diagnosis, treatment, control
A
- Recovery within 4 days (unlike CDV that progresses to death)
- Dx: clinical signs & recovery within 4 days; hemagglutination inhibition antibody titers on acute and convalescent serum (rarely)
- Tx: amantadine experimentally effective; neuraminidae inhibitors like zanamivir, oseltamivir - these prevent & treat influenza & may be used in combo with amantidin; antibiotics for secondary bacteria
- Ferrets used as influenza model; used in influenza A research to study pathogenesis, Reye’s syndrome, evaluate vaccine trials
90
Q
Rabies in ferrets
A
- Rhabdovirus, genus Lyssavirus
- Experimental infection: mean incubation period of 28-33 days, mean morbidity was 4-5 days
- Vaccinate with killed rabies vaccine at 3 mths, 1 year, then annually
- Clin signs: anxiety, lethargy, posterior paresis
- Pathology: Negri bodies may be seen in brain (not always), may be able to isolate virus from salivary glands
- Suspect ferrets that bite or scratch humans = not less than 10 day quarantine for observation
- Recent case report documented recovery and clearance of rabies virus in a ferret - survived for 100 days after onset of clinical signs with continued paraplegia
- Dx: direct IFA of brain tissue
91
Q
Rotavirus in ferrets - etiology
A
- Diarrhea in ferret kits - thought to be atypical poorly characterized rotavirus that has not been cultivated in vitro
- Atypical rotaviruses lack the rotavirus common antigen
- Definitive identification of a group C rotavirus in ferrets recently published
92
Q
Rotavirus in ferrets - epizootiology, transmission, clin signs
A
- Diarrhea, perineal soiling
- High mortality in young kits, lower mortality if over 10 days of age
- May occur in kits as young as 1-4 days & up to 6 weeks of age
- Secondary bacterial infection may increase severity of diarrhea
93
Q
Rotavirus in ferrets - pathology, diagnosis, treatment
A
- Yellow-green liquid of mucous feces in terminal colon
- Subtle small intestinal villous atrophy & epithelial cell vacuolation
- Dx: electron microscopy of centrifuged fecal pellets; CANNOT use commercially available enzyme immunoassays
- Tx: mortality reduced if kits continue nursing - syringe feed milk replacer; supportive care
- Jills develop immunity to rotavirus infection & subsequent litters are protected
94
Q
Epizootic catarrhal enteritis in ferrets - etiology, transmission
A
- A novel Alphacoronavirus = ferret enteric coronavirus (FRECV)
- Occurs when young animal introduced to a colony of adults. though susceptible animals can be infected at any age
- Virions shed in feces and saliva; intermittent shedding possible long after resolution of clinical disease
- Transmission: rapid infection by oral route
- High morbidity, low mortality
- Considered enzootic
95
Q
Epizootic catarrhal enteritis in ferrets - clin signs, diagnosis
A
- Decreased appetite, weight loss, lethargy, diarrhea - green mucoid, vomiting, dehydration
- If chronic, malabsorption can occur & feces become small, ovoid
- Elevated liver enzymes & nonspecific hematologic abnormalities in some ferrets
- Young ferrets have milder disease than older ferrets
- Dx: intestinal biopsy & histopath with IHC; RT-PCR; electron microscopy; a serologic test exists but should be evaluated in context of clinical signs
96
Q
Epizootic catarrhal enteritis in ferrets - pathology, treatment
A
- Enteritis with watery intestinal contents, enlarged mesenteric LNs
- Histo: LYMPHOCYTIC ENTERITIS WITH VILLOUS ATROPHY & necrosis and vacuolzation of enterocyte tips; villous blunting and fusion
- Lesion are in JEJUNUM & ILEUM
- Tx: aggressive oral & systemic fluid therapy; antibiotics for secondary bacteria; metronidazole
- Most detergents and disinfectants will kill environmental coronavirus
97
Q
Ferret systemic coronavirus - etiology, transmission, clin signs
A
- Systemic granulomatous disase due to ferret systemic coronavirus (FRSCV)
- Genus Alphacoronavirus - behaves similarly to FIP dry form
- Typically affects animals under 1 year of age
- Transmission: mechanism unknown, but likely ingestion
- Clin signs: lethargy, decreased appetite, diarrhea, vomiting, weight loss; some animals have neuro signs of ataxia, paresis, tremor, head tilt, seizure
98
Q
Ferret systemic coronavirus - diagnosis, pathology, treatment
A
- Histo: intralesional coronaviral nucleic acid; IHC using monoclonal antibody (FIPV3-70) will localize nucleic acid
- RT-PCR capable of differentiating FRSCV & FRECV
- Clin signs + hematology strongly suggestive - nonregenerative anemia, hyperglobulinemia, hypoalbuminemia, thrombocytopenia
- Ddx: Aleutian disease - due to FRSCV polyclonal gammopathy
- Radiography & endoscopy for palpated masses
- Necropsy: enlarged mesenteric LNs; multiple tan coalescencing nodules on serosal surfaces & mesenteric vessels
- Histo: lesions most common in liver, kidney, spleen, lung; severe pyogranulomatous inflammation often surrounding vessels that infiltrates and destroys affected parenchyma; brain = pyogranulomatous meningoencephalitis
- Tx: supportive care incl. iron in anemic animals, vitamins, gastroprotectants, immunostimulatory antibiotics like doxycycline
- Most animals die or are euthanized within weeks of diagnosis
99
Q
Bovine herpesvirus 1 in ferrets
A
- Infectious bovine rhinotracheitis (IBR)
- Isolated from liver, spleen, lung of clinically normal ferrets
- Raw beef suspected as source of infection
- In experimental infection of ferrets, IBR caused either no respiratory pathology OR acute suppurative pharyngitis
100
Q
Hepatitis E virus in ferrets
A
- Isolated from 4 ferrets in the Netherlands
- No overt signs of disease
- Relevance to ferret health or zoonotic risk unknown
101
Q
Suid herpesvirus 1 in ferrets
A
- Pseudorabies virus (PRV), Aujeszky’s disease
- Consumption of raw pork by ferrets
- Usually fatal in most species infected
102
Q
Coccidiosis in ferrets - etiology, clin signs
A
- 3 species of Isospora and Eimeria reported in ferrets: Isospora laidlawi, Eimeria furonis, Eimeria ictidea
- Transmission: ingestion of sporulated oocysts
- Clin signs: usually subclinical; diarrhea, lethargy, dehydration; rectal prolapse; one case of biliary infestation with E. furonis
- Clin signs more common in young newly acquired ferrets after a stressful event
103
Q
Coccidiosis in ferrets - diagnosis, treatment
A
- Dx: fecal float, direct wet mount; infestation of biliary tract resulted in changes on serum chemistry
- Pathology: jejunum & ileum - villous and epithelial thickening; parasitic cysts and microorganisms within epithelium; mild granulomatous inflammation in villar lamina propria
- Ddx: GI foreign body; dietary indiscretion, nutritional, inflammatory, infectious, other systemic diseases - proliferative colitis, salmonellosis, giardiasis, rotavirus, campylobacteriosis, eosinophilic gastroenteritis
- In biliary case: hepatomegaly, enlarged firm bile ducts, thickened gallbladder wall
- Control: good husbandry; cleaning cages with strong ammonium hydroxide solution; heat treatment of surfaces and utensils
- Tx: sulfadimethozine for 6 days; ponazuril (triazine coccidiocidal drug) for 10 days
- As with dogs and cats, the complete elimination of a coccidial infection requires an immunocompetent host
104
Q
Cryptosporidiosis in ferrets - etiology, transmission, clin signs
A
- Etiology: Cryptosporidium spp.
- Class Sporozoa, Subclass Cocidia
- Inhabits respiratory and intestinal epithelium of birds, reptiles, mammals. fish
- Transmission: ingestion of sporulated oocysts in contaminated food, water; life cycle similar to other coccidian parasites; autoinfection characteristic of life cycle
- Clin signs: subclinical in both immunocompetent & immunosuppressed ferrets reported; otherwise nonspecific clinical signs with death possible in 48-72 hr
105
Q
Cyrptosporidiosis in ferrets - diagnosis, pathology, treatment
A
- Dx: sugar solution centrifugation or fecal sedimentation using formalin-ether or formalin-ethyl acetate; direct fecal smear with methanol or heat fixing & stained with acid-fast - oocysts small compared to other coccidia - spherical to ellipsoidal; acid-fast; oocyst residuum is seen as a refractive dot under phase-contrast
- Pathology: spherical to ovoid 2-5 um diameter organisms associated with brush border of villi; mild eosinophilic infiltrate in lamina propria of small intestine; ILEUM MOST COMMON HEAVILY INFECTED SECTION of small intestine
- Tx: no known definitive treatment; supportive/symptomatic care; infections self-limiting in immunocompetent
- ZOONOTIC
- Drying, freeze-thawing, and steam cleaning inactivate the organism; few effective commercial disinfectants
106
Q
Sarcoptic mange in ferrets
A
- Sarcoptes scabiei
- Transmission: direct contact with infected hosts or fomites
- Ferrets have Generalized or Pedal Form
- Generalized: lesions are focal or generalized alopecia with intense pruritis
- Pedal: lesions confined to toes and feet; feet become swollen with scabbing, nails may be deformed or lost
- Dx: skin scraping or removing crusts, breaking them up, & clearing with 10& KOH for microscopic exam
- Ddx: other pruritic external parasites like fleas; demodicois causes mild pruritis and alopecia in ferrets
- Tx: Pedal = trim claws, remove scabs after softening in warm water; ivermectin SC or selamectin or lime sulfur dips; shampoos or soaks to reduce pruritis; antibiotics for secondary bacteria
107
Q
Demodicosis in ferrets
A
- Demodex spp.
- Found in normal skin, not considered contagious; predisposing factors incl immunologic or genetic conditions
- Clin signs: alopecia, pruritis, orange discoloration of skin behind ears or on ventral abdomen & accompanying seborrhea
- Dx: deep skin scraping; skin biopsy may be needed in chronic cases with thickened skin
- Pathology: mites with a short, blunted abdomen similar to Demodex criceti; epidermis hypertrophic, mild superficial orthokeratotic hyperkeratosis, mild perivascular & superficial mixed cellular infiltrate
- Ddx: sarcoptic mange, fleas, primary/secondary bacterial dermatitis
- Tx: amitraz dip; imidacloprid-moxidectin; ivemectin orally or topically; selamectin
108
Q
Ear mites in ferrets
A
- Otodectes cynotis
- Transmission: direct contact with infested animal; entire life cycle completed in 3 weeks
- Clin signs: usually asymptomatic; head shaking, mild to severe pruritis with inflammation & excoriation; secondary otitis interna with ataxia, circling, torticollis, Horner’s syndrome; brownish-black waxy discharge
- Dx: otoscopic exam, microscope evaluation of ear slides
- Tx: topical treatments more efficacious than injectable; ivermectin; due to anatomic characteristics of ferret ear, instillation of drops into the ear canal is of very limited efficacy; selamectin; imidacloprid-moxidectin; can give medications partially in ear canal & partially at interscapular region
- High doses of ivermectin (0.2 mL of 1% solution) administered to jills at 2-4 weeks gestation resulted in high rates of congenital defects
109
Q
Fleas in ferrets
A
- Ctenocephalides species
- Transmission: direct contact with another infested animal or flea-infested environment
- Clin signs: asymptomatic; mild to intense pruritis and alopecia of dorsal thorax and neck
- Dx: clin signs, identification of fleas or flea excrement
- Ddx: sarcoptic mange, demodex
- Tx: concurrent treatment of environment & all animals in household is essential; rotenone or pyrethrin powders or sprays; selamectin topical; imidacloprid topical
110
Q
Pneumocystis carinii in ferrets
A
- Fungus
- Inhabits lungs of many different species; recent transmission studies suggest these fungi are highly species specific
- Clin signs: only seen in immunocompromized ferrets (such as induced using high dose steroids)
- Pathology: interstitial pneumonitis with mononuclear cell infiltrates
- Dx: cysts and trophozites are evident with Gomori methanamine-silver nitrate and Giemsa on bronchoalveolar lavage
- Tx: trimethoprim-sulfamethoxazole probably controls but does NOT eliminate infection
111
Q
Mucormycosis in ferrets
A
- Ferrets susceptible o secondary fungal infection of outer ear canal with Absidia corymbifera or Malassezia spp.
- These fungi widespread in environment & will cause secondary fungal infection in ears of ferrets infested with Otodectes cynotis
- Dx: impression of ear exudates
- Tx: eradicate underlying mite infestation followed by oral and topical ketoconazole, miconazole and polymyxin B
112
Q
Dermatomycosis in ferrest
A
- Microsporum canis & Trichophyton mentagrophytes
- ZOONOTIC
- Control infection with general disinfection and destruction of contaminated beddings
- Clin signs: circumscribed areas of alopecia inflammation that begin as small papules & spread peripherally in a scaly inflamed ring
- Dx: yellow-green fluorescence of M. canis under UV light; skin scrapings digested with 10% KOH
- Tx: griseofulvin causes clinical remission but may not clear infx
113
Q
Cryptococcosis in ferrets
A
- Cryptococcus neoformans, Cryptococcus gatti
- Immune suppression might be a contributing factor
- Cryptococcus is found in soil, bird droppings, and trees
- Prognosis is guarded and treatment is usually difficult
- Tx: itraconazole for 10 months resulted in a successful outcome for C. neoformans variety grubii isolated from an enlarged submandibular LN
114
Q
Other ectoparasites of ferrets
A
- Hypoderma bovis: granulomatous masses in cervical region
- Cuterebra larvae: subdermal cysts in subcutis of nec
- Flesh fly: infestation reported in commercially reared mink and ferrets housed outdoors
- Ticks: may be found on ferrets housed outdoors
115
Q
Heartworm in ferrets - etiology, epizootiology, transmission
A
- Dirofilaria immitis - filarial parasite transmitted by mosquitos
- Microfilaria ingested by mosquitos and, after 2 molts, become infective 3rd stage larvae - infected larvae deposited into skin when mosquitos feed - larvae find way into body and migrate SC to thorax and eventually heart
- Primary reservoir of infection is dogs, but heartworm may be found in a variety of mammals
- All species except wild & domestic canids, domestic felines, ferrets, and California sea lions are considered aberrant hosts
116
Q
Heartworm in ferrets - clin signs, dx, treatment
A
- Weakness, lethargy, depression, dyspnea, cyanosis, anorexia, dehydration, cough, pale MMs; moist lung sounds, muffled heart sounds; pleural or abdominal effusion; caval syndrome, mild anemia, biliverdinuria - may be of increased diagnostic value for this condition in ferrets
- Dx: clin signs, radiography/US, microfilaremia - not consistent, testing for heartworm antigen may be more useful
- Pathology: cardiomegaly, pleural and/or abdominal fluid and pulmonary congestion; adult worms in R atrium, R ventricle, pulmonary artery, cranial & caudal vena cava; microfilaria in small & large vessels in lungs
- Ddx: primary cardiac disease - DCM; other systemic or pulmonary diseases
- Tx: Prevent with monthly oral ivermectin or topical selamectin year-round (0.006 mg/kg body weight monthly); treatment with thiacetarsemide (same precautions as dogs - antithromboic therapy, treatment for heart failure, strict cage confinement); ivermectin until clin sins & microfilaremia resolve; melarsomine NOT recommended d/t adverse reactions
117
Q
Other nematodes in ferrets
A
-Ferrets are susceptible to infection with: Toxascaris leonina; Toxocara cati; Ancylostoma spp.; Dipylidium caninum; Mesocestoides spp.;
Atriotaenia procyonis; Trichinella spiralis; Filaroides martis; and Spiroptera nasicola
118
Q
Pregnancy toxemia in ferrets - etiology
A
- Most common in primiparous jills carrying large litters; an inadvertant fast in late pregnancy is sometimes indicated
- At least 75% of jills carrying more than 8 kits will develop if subjected to 24 hr of food withdrawal
- Any jill with 15 of more kits may develop because abdominal space inadequate for uterus & amount of food required
- Abnormal energy metabolism with hyperlipiemia, hypoglycemia, ketosis, hepatic lipidosis, decreased T4 and T3 levels
- Excessive mobilization of free fatty acids
119
Q
Pregnancy toxemia in ferrets - clin signs, diagnosis, pathology, treatment
A
- Anorexia, lethargy, melena, dehydration, easily epilated hair
- Ddx: dystocia, metritis, pyometra, septicemia, renal failure, Helicobacter mustelae-induced gastric ulcer
- Dx: azotemia, hypocalcemia, hypoproteinemia, elevated liver enzymes, anemia
- Pathology: tan or yellow discolored liver, gastric hemorrhage, gravid uterus
- Tx: if jill within a day of delivery, C-section and intensive postop support - force feeding gruel of high quality cat food & ferret chow, IV fluids with glucose, supplemental heat’ perform C-section under isoflurane or sevoflurane b/c metabolism of injectable agents prolonged by hepatic dysfunction
- Agalactia common after C-section - hand feed or cross foster kits
- Develop toxemia before 40 days of gestation = fluids & nutritional support until C-section can be performed
- Prevention: feed highly palatable diet with >20% fat and >35% crude protein, avoid stress & dietary changes
120
Q
Hyperestrogenism in ferrets - etiology, clin signs
A
- Ferrets are induced ovulators and may remain in persistent estrus if they are not bred or if estrus is not terminated chemically or by OVH
- Estrogen-indued anemia possible in jills that remain in estrus for more than 1 month
- Hyperestrogenism causes bone marrow hypoplasia of all cell lines in half of ferrets in prolonged estrus
- Clin signs: vulvar enlargement, bilaterally symmetric alopecia of tail and abdomen, weakness, anorexia, depression, lethargy, weight loss, bacterial infection, mucopurulent vaginal discharge
- Initial neutrophilia & thrombocytosis then lymphopenia, thrombocytopenia, neutropenia, anemia
- Anemia begins as normocytic normochromic & progresses to macrocytic hypochromic
- Coagulopathy assoc w/ hepatic dysfunction, thrombocytopenia = bleeding, pallor, melena, petechiation or ecchymosis, subdural hematoma, hematomyelia
121
Q
Hyperestrogenism in ferrets - pathology, treatment
A
- Tissue pallor, light tan to pale pink bone marrow, hemorrhage, bronchopneumonia, hyddrometra, pyometra, mucopurulent vaginitis
- Histo: cystic endometrial hypoplasia, hemosiderosis, diminised splenic extramedullary hemtopoiesis, mild to moderate hepatic lipiosis
- Tx: terminate estrus & supportive care with antibiotics, blood transfusion, B vitamins, nutritional support
- Estrus may be terminated by injection of 50-100 IU HCG or 20 ug of GnRH, repeated 1 week later if needed; OVH
- PCV 25% or greater - good prognosis; PCV 15-25% guarded & may need blood transfusion; PCV less than 15% - poor prognosis
- Repeated administration of hCG may result in sensitization and anaphylaxis - incoordination, tremor, vomiting, diarrhea - reverse with diphenhydramine; GnRH is smaller molecule = anaphylaxis less likely, GnRH implant is available
- Estrogen induced anemia can be avoided by OVH, use of vasectomized hovs, or pharmacologic termination of estrus initiated 10 days after estrus onset
122
Q
Hyperammonemia in ferrets
A
- Administration of arginine-free diets to young ferrets fasted for 16 hr leads to hyperammonemia and encephalopathy within 2-3 hr
- Exacerbation of signs may be achieved by challenging young ferrets with influenza virus and aspirin - constitutes a model of Reye’s syndrome in children
- Clin signs: lethargy, aggressiveness; then prostration, coma, death
- Presumably occurs because of inability of ferrets to produce adequate amounts of ornithine from non-arginine precursors - detoxificaton of ammonia is therefore compromised
- Ferrets older than 18 mths are unaffected by arginine-free diets
123
Q
Zinc toxicosis in ferrets
A
- Ferrets of all ages are susceptible
- Leaching of zinc from steam-sterilize galvanized food and water bowls
- Clin signs: pallor, posterior weakness, lethargy
- Dx: elevated levels of zinc in kidney and liver
- Pathology: kidneys enlarged, pale, soft; livers orange; gastric hemorrhage
- Histo: glomerular collapse, tubular dilation, tubular proteinaceous debris, focal cortical fibrosis, hepatic periacinar infiltration, depresstion of erythroid series
- Avoid galvanized materials
124
Q
Hypothyroidism in ferrets
A
- Clin signs: obesity, lethargy, decreased activity, excessive sleeping
- Dx: measure T4 levels using human recombinant TSH
- Tx: oral levothyroxine every 12 hr
125
Q
Traumatic disorders in ferrets
A
- Fighting: separate hobs at 12 weeks of age to avoid
- Traumatic elbow luxation: common in ferrets; typically occurs when animal changes directions after getting a leg caught in cage flooring; open reduction should be used because closed reduction rarely successful = tranarticular pin for 4 weeks with leg splinted until after pin removal
126
Q
Iatrogenic disorders in ferrets
A
- Hydronephrosis due to ureter ligation & ovarian remnants = both related to OVH surgery
- Ovarian remnants assoc w/ estrus, vulvar enlargement, alopecia
127
Q
4 major categories of neoplasia in ferrets
A
- Pancreatic islet cell tumors
- Adrenocortical cell tumors
- Lymphoma
- Skin cancers
128
Q
Insulinoma in ferrets
A
- Functional pancreatic islet cell tumors = most common neoplasm in ferrets
- In ferrets as young as 2 years, typically later onset at 4-5 years
- Clin signs: weight loss, vomiting, ataxia; weakness with posterior paresis or collapse, splenomegaly, lymphcytosis; signs often intermittent or episodic
- Hypoglycemia caused by excess production of insulin in neoplastic Beta-cells may cause tremors, disorientation, seizures
- Excessive salivation and pawing at mouth
- Dx: presumptive based on clin signs + hypoglycemia (check after 4 hr fasting period) - fasting glucose below 60 mg/dL considered diagnostic; 60-85 mg/dL suspect; concurrent hyperinsulinemia, but insulin secretion in affected ferrets can be sporadic; histology can provide definitive diagnosis = proliferation of pancreatic Beta-cells; can have local recurrence or mets to LNs, mesentery, spleen, liver
- Ddx: anorexia, starvation, hepatic disease, sepsis, nonpancreatic neoplasia
- Tx: medical management with prednisone +/0 diazoxide along with frequent feeding of high-protein meals; surgery recommended for animals that are healthy enough
129
Q
Adrenal tumors in ferrets
A
- Second most common type of neoplasia in ferrets
- Generally diagnosed between 3-6 years of age
- Clin signs: asymptomatic; weight loss, bilateral symmetrical alopecia +/- pruritis
- Clin signs directly related to increase of sex steroids in the blood resulting in estrogen toxicity
- Difference between this condition and typical Cushing presentation is the production in affected ferrets of a significant increased of sex steroids by the zona reticularis and NOT significant levels of cortisol from the zona fasciculata
- Sex steroids that are usually elevated are estradiol, 17-hydroxyprogesterone, testosterone, androstenedione
- Estrus-like vulva swelling in females; prostatic changes and cystitis in males
- Ddx: ovarian remnant
- Dx: palpation reveals cranial abdominal masses, US shows increased adrenal size; serum assay of sex hormones
- Alopecia can be seasonally intermittent
- Adrenal cortical hyperplasia is extremely common in aging ferrets, even those not showing clinical signs
- Tx: medical management: monthly injection of Lupron (leuprolide acetate) = GnRH superagonist & stops production of LH and FSH - resistant to Lupron may develop over time; Deslorelin implants are treatment of choice; GnRH vaccine for prevention; melatonin - directly inhibits GnRH release; Ferretonin (melatonin implant); surgical exploration and removal of enlarged adrenals; ultrasound-guided alcohol injection into affect adrenal
- Frequently a tumor of the right adrenal will invade into the vena cava = partial resection or removal of vena cava needed; collateral vessels will make up for vena cava; survivors need aggressive fluid therapy for 2-3 days post-op
- Histo: well-differentiated cells with a granular or vacuolated cytoplasm; adrenal cell carcinomas are less commonly found than adenomas & are larger, more pleomorphic, more invasive; mets can occur but are rare
130
Q
Bilateral adrenalectomy in ferrets
A
- It is possible to remove both adrenal glands at the same time without creating significant hormonal issues
- Animals should be medicated with dexamethasone during postop recover, & oral prednisone for a few weeks after surgery
- Supplementation with glucocorticoids sometimes needed is the gland remaining after unilateral adrenalectomy has been suppressed by the hyperactive one
131
Q
Lymphoma in ferrets - etiology, clinical signs
A
- Seen in all ages; an aggressive form is often seen in juvenile ferrets (less than 2 years of age) - mediastinal mass if often found
- Older ferrets (greaters than 2 years old) more likely to develop more indolent form - multicentric or GI lymphoma
- Potential etiologies: a retrovirus distinct to FeLV; chronic immune stimulation d/t ADV or Helicobacter mustelae (seems responsible for a specific type of gastric B-cell lymphoma)
- Clin signs: often chronic, nonspecific signs - weight loss, anorexia, lethargy, splenic or hepatic enlargement, cutaneous involvement; anemia, lymphopenia or lymphocytosis; atypical lymphocytes in circulation; hypercalcemia with T cell lymphoma; dyspnea with mediastinal mass; elevated liver values, azotemia
- Dx: FNA of masses, radiographs or US; IHC of affected tissues to determine cell immunophenotype
132
Q
IHC for ferret lymphoma
A
- Anti-CD3 = B cell lymphoma
- Anti-CD79a = T cell lymphoma
133
Q
Lymphoma in ferrets - pathology, treatment
A
- Tan colored masses in lymph nodes, spleen, liver, other organs; diffuse involvement may cause enlargement of these organs or thickening of wall of stomach or intestines
- Histo: neoplastic lymphocytes
- Tx: surgery, chemotherapy, radiation; simplest form of chemotherapy is prednisolone/prednisone - will achieve partial or complete, short term remission
- Chemotherapy may be less effective in ferrets receiving chronic immunosuppression; most chemo regimens are modified feline lymphoma protocols
- The more rapidly progressive form seen in younger ferrets should likely be treated more aggressively than the indolent form seen in adults
- Doxorubicin, and to a lesser extent vincristine, can cause severe tissue sloughing if there is extravasation
134
Q
Skin tumors in ferrets
A
- Mast cells tumors are most common integumentary tumors in ferrets - occur anywhere on body with associated alopecia, crusty ulceration, pruritis; histo: well differentiated mast cells with metachromatic cytoplasmic granules - toluidine blue stain
- Basal cell tumors: firm plaques or pedunculated nodules that are white or pink; may grow rapidly and ulcerate; most are benign; Ddx: squamous cell carcinoma, apocrine gland adenocarcinoma
- Chordomas: not epithelial cell tumors, but often present as firm masses on tail, may ulcerate overlying skin; arise along axial skeleton from notochord remnants, slow-growing; generally do not reoccur after tail amputation; prognosis guarded for rare cervical region chordomas - mets documented
135
Q
Placental-umbilical entanglement in ferrets
A
- Has been assoc w/ fine particle bedding, large litters, short kit-birth intervals
- Jills may neglect to clean placentas, or kits may be born so rapidly there is not adequate time
- Entangled kits may die d/t dehydration, hypothermia, hypoglycemia
- Tx: dissection under a heat lamp or on a heated surface to free kits; cords should be cut as far away from umbilicus as possible
- Parturition should be supervised, if possible, to avoid entanglement
136
Q
Congenital defects in ferrets
A
- Neural tube defect
- Gastrochisis
- Cleft palate
- Amelia
- Corneal dermoids
- Cataracts
- Supernumerary incisors
- Cystic or polycystic kidneys
- Cystic genitourinary anomalies assoc w/ prostate, bladder, proximal urethra likely develop secondary to aberrant hormone secretion by adrenocortical tumors
- Newborn ferrets normally born with closed orbital fissure and are prone to developing subpalpebral abscesses
137
Q
Cardiomyopathy in ferrets
A
- Common in aging ferrets
- Dilatative form most commonly diagnosed
- Clin signs: lethargy, weight loss, anorexia; hypothermia, tachycardia, cyanosis, jugular distension, respiratory distress
- Dx: heart murmur/muffled sounds; hepato- & splenomegaly; radiographs; ECG
- Tx: supportive care, diuretics, inotropic drugs
- Long term prognosis is guarded to poor
138
Q
Splenomegaly in ferrets
A
- Common finding in ferrets
- May be related to another disease (insulinoma, cardiomyopathy, adrenal tumor, lymphoma, splenic sequestration of erythrocytes with anesthesia) or of unknown significant
- Histo: extramedullary hematopoiesis (EMH) - may be incidental or play role in chronic anemia that may respond to splenectomy = syndrome called hypersplenism
139
Q
Eosinophilic gastroenteritis in ferrets
A
- Idiopathic disorder with peripheral eosinophilia of 10-35% (but may not be elevated peripherally), hypoalbuminemia, diffuse infiltration of GI tract with eosinophils
- Incidence is variable
- Clin signs: chronic weight loss, anorexia, diarrhea, vomiting
- Eosinophilic granulomas in mesenteric LNs; sometimes lung or liver may be involved
- Splendore-Hoeppli material in inflamed LNs (Giemsa stain) - this is usually associated with helminths, bacteria, fungi, foreign bodies
- Tx: supportive care for enteritis; ivermectin and corticosteroids may be beneficial
140
Q
Megaesophagus in ferrets
A
- Clin signs: weight loss, anorexia, difficulty eating, repeated regurgitation
- Cause generally unknown
- Prognosis is poor, despite efforts at supportive care
141
Q
Disseminated idiopathic myofasciitis in ferrets
A
- Emerging ferret disease first described in 2003
- Inflammation of muscle and surrounding tissue
- Ferrets under 18 months most commonly affected
- Clin signs: fever, lethargy, depression, paresis, inappetance; lumbosacral or hind limb pain
- Progressive disability leads to euthanasia in most cases
- PE: wasting, muscle atrophy, lymphadenopathy and splenomegaly
- ALT may be elevated but CK is not; hypoproteinemia and hypoglobulinemia sometimes observed
- Dx: muscle biopsy
- Pathology: areas of pallor or white streaks in various muscle groups including esophagus, diaphragmm, both axial and appendicular skeletal muscle
- Histo: muscle fiber strophy, neutrophilic to pyogranulomatous infiltrate within and around muscle fibers of smooth, cardiac, and skeletal muscle; *transmural and circumferential esophageal infiltrate along the length of the organ is characteristic
- Tx: combination of prednisone, cyclophosphamide, chloramphenicol may be successful
142
Q
Subpleural histiocytosis/Pleural lipidosis/Lipid pneumonia in ferrets
A
- Gray, yellow, or white small raised lesion on surface of lungs
- Histo: superficial thickening of lung tissue with mononuclear cell infiltration and varying degrees of fibrosis, with or without cholesterol-like clefts
- Etiology unknown; appears to be incidental lesion
